Advancements in Boundary Layer Theory: Implications for Aerodynamics and Heat Transfer

Abstract

Boundary layer theory has long served as a cornerstone of fluid mechanics, underpinning our understanding of viscous flow, aerodynamic performance, and thermal management. In recent decades, significant advancements in both analytical and computational techniques have deepened insights into boundary layer behavior, enabling more accurate prediction and control of flow separation, transition, turbulence, and heat transfer processes.

This review article examines the latest innovations in boundary layer theory, discussing their implications for aerodynamic design, heat transfer optimization, and energy-efficient engineering systems. The discussion encompasses novel analytical models, high-fidelity computational methods, and state-of-the-art experimental techniques, highlighting their role in improving aircraft performance, turbine efficiency, vehicle aerodynamics, and thermal management systems. Advances in computational fluid dynamics (CFD), including direct numerical simulation (DNS), large eddy simulation (LES), and machine learning-based turbulence modeling, have significantly enhanced the accuracy of boundary layer predictions. Experimental methodologies such as particle image velocimetry (PIV), hot-wire anemometry, and infrared thermography have further contributed to validating and refining theoretical models.

Furthermore, boundary layer control techniques, including passive strategies such as riblets and micro-vortex generators (MVGs), as well as active approaches like plasma actuators and synthetic jets, are explored in the context of drag reduction, noise mitigation, and heat transfer enhancement. The review also discusses the implications of hypersonic boundary layer transition, addressing the challenges posed by compressibility effects, extreme heat loads, and high-speed aerodynamics.